Alpha-particle Measurements Needed for Burning Plasma Experiments (open access)

Alpha-particle Measurements Needed for Burning Plasma Experiments

The next major step in magnetic fusion studies will be the construction of a burning plasma (BP) experiment where the goals will be to achieve and understand the plasma behavior with the internal heating provided by fusion-generated alpha particles. Two devices with these physics goals have been proposed: the International Thermonuclear Experimental Reactor (ITER) and the Fusion Ignition Research Experiment (FIRE). Extensive conceptual design work for the instrumentation to try to meet the physics demands has been done for these devices, especially ITER. This article provides a new look at the measurements specifically important for understanding the physics aspects of the alpha particles taking into account two significant events. The first is the completion of physics experiments on the Joint European Torus (JET) and the Tokamak Fusion Test Reactor (TFTR) with deuterium-tritium fueling with the first chances to study alpha physics and the second is the realization that relatively compact plasmas, making use of advanced tokamak plasma concepts, are the most probable route to burning plasmas and ultimately a fusion reactor.
Date: September 26, 2001
Creator: Young, Kenneth M.
Object Type: Report
System: The UNT Digital Library
Catalysis of PAH Biodegradation by Humic Acid Shown in Synchrotron Infrared Studies (open access)

Catalysis of PAH Biodegradation by Humic Acid Shown in Synchrotron Infrared Studies

The role of humic acid (HA) in the biodegradation of toxic polycyclic aromatic hydrocarbons (PAHs) has been the subject of controversy, particularly in unsaturated environments. By utilizing an infrared spectromicroscope and a very bright, nondestructive synchrotron photon source, we monitored in situ and, over time, the influence of HA on the progression of degradation of pyrene (a model PAH) by a bacterial colony on a magnetite surface. Our results indicate that HA dramatically shortens the onset time for PAH biodegradation from 168 to 2 h. In the absence of HA, it takes the bacteria about 168 h to produce sufficient glycolipids to solubilize pyrene and make it bioavailable for biodegradation. These results will have large implications for the bioremediation of contaminated soils.
Date: September 26, 2001
Creator: Holman, Hoi-Ying N.; Nieman, Karl; Sorensen, Darwin L.; Miller, Charles D.; Martin, Michael C.; Borch, Thomas et al.
Object Type: Article
System: The UNT Digital Library
Data Catalog for Models Simulating Release of Contaminants from Hanford Site Waste Sources (open access)

Data Catalog for Models Simulating Release of Contaminants from Hanford Site Waste Sources

This report provides summaries of release models used in Hanford Site assessments published over the past 14 years (1987 to 2001). Mathematical formulations that commonly have been used in recent years (i.e., salt-cake, cement, soil-debris, reactor block, glass, and corrosion) are described, along with associated parameter definitions and their units. Tables in this report provide links to data sources needed to implement the models. These links enable users to quickly locate the specific release model information and data sources they need for applying the models to future to site assessments.
Date: September 26, 2001
Creator: Riley, Robert G. & Lopresti, Charles A.
Object Type: Report
System: The UNT Digital Library
Diagnostics of ST Plasmas in NSTX: Challenges and Opportunities (open access)

Diagnostics of ST Plasmas in NSTX: Challenges and Opportunities

This paper will highlight some of the challenges and opportunities present in the diagnosis of spherical torus (ST) plasmas on the National Spherical Torus Experiment (NSTX) and discuss the corresponding diagnostic development that is presently underway. After a brief description of diagnostic systems currently installed, examples of ST-specific diagnostic challenges will be highlighted, as will another case, where the ST configuration offers opportunities for new measurements.
Date: September 26, 2001
Creator: Johnson, D.; Efthimion, P.; Foley, J.; Jones, B.; Mazzucato, E.; Park, H. et al.
Object Type: Report
System: The UNT Digital Library
Imaging the separation of cathodic arc plasma and macroparticles in curved magnetic filters (open access)

Imaging the separation of cathodic arc plasma and macroparticles in curved magnetic filters

None
Date: September 26, 2001
Creator: Anders, Andre
Object Type: Article
System: The UNT Digital Library
Low-Temperature, Anode-Supported High Power Density Solid Oxide Fuel Cells With Nanostructured Electrodes (open access)

Low-Temperature, Anode-Supported High Power Density Solid Oxide Fuel Cells With Nanostructured Electrodes

Anode-supported solid oxide fuel cells with Ni + yttria-stabilized zirconia (YSZ) anode, YSZ-samaria-doped ceria (SDC) bi-layer electrolyte and Sr-doped LaCoO{sub 3} (LSC) + SDC cathode were fabricated. Fuel used consisted of H{sub 2} diluted with He, N{sub 2}, H{sub 2}O or CO{sub 2}, mixtures of H{sub 2} and CO, and mixtures of CO and CO{sub 2}. Cell performance was measured at 800 C with above-mentioned fuel gas mixtures and air as oxidant. For a given concentration of the diluent, the cell performance was higher with He as the diluent than with N{sub 2} as the diluent. Mass transport through porous Ni-YSZ anode for H{sub 2}-H{sub 2}O, CO-CO{sub 2} binary systems and H{sub 2}-H{sub 2}O-diluent gas ternary systems was analyzed using multicomponent gas diffusion theory. At high concentrations of the diluent, the maximum achievable current density was limited by the anodic concentration polarization. From this measured limiting current density, the corresponding effective gas diffusivity was estimated. Highest effective diffusivity was estimated for fuel gas mixtures containing H{sub 2}-H{sub 2}O-He mixtures ({approx}0.34 cm{sup 2}/s), and the lowest for CO-CO{sub 2} mixtures ({approx}0.07 cm{sup 2}/s). The lowest performance was observed with CO-CO{sub 2} mixture as a fuel, which in part was attributed to …
Date: September 26, 2001
Creator: Virkar, Anil V.
Object Type: Report
System: The UNT Digital Library
A Proposal for Establishing a Free Market Basis for Plant Genome Information Exchange (open access)

A Proposal for Establishing a Free Market Basis for Plant Genome Information Exchange

The current situation of genomics information exchange is reminiscent of some Third World cities, where residents despair they will ever get official utility service and therefore tap into power, phone, and gas sources with makeshift connections. Thus, each genomics grant spawns yet another idiosyncratic Web site, with makeshift links to whatever random Web sites the PI is most familiar with. There are few standards for semantics of data, and fewer standards for automating the interchange or integration of these autonomous Web sites. The US Plant Genome Initiative (PGI) has been enthusiastic contributor to this proliferation of chaotic Web sites, but to its credit it appears to be the first major program to attempt to find a solution. Some of us from the earliest days of the Human Genome Program have been acutely aware of the problems of genomic data integration, since long before the Web appeared and made the problem exponentially harder to resolve. We have seen large scale attempts, and subsequent failures or inadequacies, of many potential solution approaches (i.e., database federation, classical data warehousing, centralized data, etc.) and believe we know at least some of the reasons they still remain inadequate. It is our opinion that the only …
Date: September 26, 2001
Creator: Slezak, T.
Object Type: Article
System: The UNT Digital Library
Rapid thermal annealing of InAs/GaAs quantum dots under a GaAs proximity cap (open access)

Rapid thermal annealing of InAs/GaAs quantum dots under a GaAs proximity cap

None
Date: September 26, 2001
Creator: Babinski, Adam; Jasinski, J.; Bozek, R.; Szepielow, A. & Baranowski, J. M.
Object Type: Article
System: The UNT Digital Library
SNS Inner Plug Shipping Cask Analysis (open access)

SNS Inner Plug Shipping Cask Analysis

Calculations were performed to evaluate the dose rates outside the shipping cask containing the Spallation Neutron Source (SNS) inner plug assembly. The analysis consisted of simulating the proton beam interaction with the SNS target, activation calculations with the determined neutron flux levels and assumed SNS operation schedule, and calculation of the decay gamma-rays propagation through the inner plug and shipping cask. Several materials were considered for the inner plug. The results provide guidance for the finalization of the plug design.
Date: September 26, 2001
Creator: Remec, I
Object Type: Article
System: The UNT Digital Library
VOC Control in Kraft Mills (open access)

VOC Control in Kraft Mills

The formation of volatile organic compounds (VOCs), such as methanol, in kraft mills has been an environmental concern. Methanol is soluble in water and can increase the biochemical oxygen demand. Furthermore, it can also be released into atmosphere at the process temperatures of kraft mill-streams. The Cluster Rule of the EPA now requires the control of the release of methanol in pulp and paper mills. This research program was conducted to develop a computer simulation tool for mills to predict VOC air emissions. To achieve the objective of the research program, much effort was made in the development of analytical techniques for the analysis of VOC and determination of vapor liquid partitioning coefficient of VOCs in kraft mill-streams using headspace gas chromatography. With the developed analytical tool, methanol formation in alkaline pulping was studied in laboratory to provide benchmark data of the amount of methanol formation in pulping in kraft mills and for the validation of VOC formation and vapor-liquid equilibrium submodels. Several millwide air and liquid samplings were conducted using the analytical tools developed to validate the simulation tool. The VOC predictive simulation model was developed based on the basic chemical engineering concepts, i.e., reaction kinetics, vapor liquid equilibrium, …
Date: September 26, 2001
Creator: Zhu, J.Y.; Chai, X.-S.; Edwards, L.L.; Gu, Y.; Teja, A.S.; Kirkman, A.G. et al.
Object Type: Report
System: The UNT Digital Library
VOC Control in Kraft Mills - Final Report: Task A and Task B (open access)

VOC Control in Kraft Mills - Final Report: Task A and Task B

The formation of volatile organic compounds (VOCs), such as methanol, in kraft mills has been an environmental concern. Methanol is soluble in water and can increase the biochemical oxygen demand. Furthermore, it can also be released into atmosphere at the process temperatures of kraft mill-streams. The Cluster Rule of the EPA now requires the control of the release of methanol in pulp and paper mills. This research program was conducted to develop a computer simulation tool for mills to predict VOC air emissions. To achieve the objective of the research program, much effort was made in the development of analytical techniques for the analysis of VOC and determination of vapor liquid partitioning coefficient of VOCs in kraft mill-streams using headspace gas chromatography. With the developed analytical tool, methanol formation in alkaline pulping was studied in laboratory to provide benchmark data of the amount of methanol formation in pulping in kraft mills and for the validation of VOC formation and vapor-liquid equilibrium submodels. Several millwide air and liquid samplings were conducted using the analytical tools developed to validate the simulation tool. The VOC predictive simulation model was developed based on the basic chemical engineering concepts, i.e., reaction kinetics, vapor liquid equilibrium, …
Date: September 26, 2001
Creator: Zhu, J.Y.; Chai, X.-S.; Edwards, L.L.; Gu, Y.; Teja, A.S.; Kirkman, A.G. et al.
Object Type: Report
System: The UNT Digital Library
What's New: Fall 2001 Update (open access)

What's New: Fall 2001 Update

Bi-annual newsletter features articles on HEV/LSV compliance advisory, biodiesel fuel use growth in 2000, Texas Department of Transportation, and the Credit Trades Bulletin Board.
Date: September 26, 2001
Creator: White, H.
Object Type: Book
System: The UNT Digital Library